. The bee-keeper's guide; or, Manual of the apiary. Bees. OR, MANUAI, OF THB APIARY. 8S where bathes the digestive canal, and thus easily receives nutriment, or gives waste by osmosis ; everywhere surrounds the tracheae or air-tubes—the insect's lungs—and thus receives that most needful of all food, oxygen, and gives the baneful carbonic acid ; everywhere touches the various organs, and gives and takes as the vital operations of the animal require. The heart, like animal vessels, generally, consists of an outer serous membrane, an inner, epithelial coat, and a middle muscular layer. Owing to t
. The bee-keeper's guide; or, Manual of the apiary. Bees. OR, MANUAI, OF THB APIARY. 8S where bathes the digestive canal, and thus easily receives nutriment, or gives waste by osmosis ; everywhere surrounds the tracheae or air-tubes—the insect's lungs—and thus receives that most needful of all food, oxygen, and gives the baneful carbonic acid ; everywhere touches the various organs, and gives and takes as the vital operations of the animal require. The heart, like animal vessels, generally, consists of an outer serous membrane, an inner, epithelial coat, and a middle muscular layer. Owing to the opaque crust, the pulsations of the heart can not generally be seen ; but in some transparent larvae, like many maggots, some parasites—those of our com- mon cabbage butterfly show this admirably—and especially in aquatic larvs, the pulsations are plainly visible, and are most interesting objects of study. The heart, as shown by Ivyonet, is held to the dorsal wall by muscles (Fig. 32, m). Beneath the heart are muscles which. Fig. 32. Fig. Portion of Beart of an Insect, after Packard. H Heart. ' m Muscles, o Openings. Diagram of Heart, from Cowan. to quote from Girard, form a sort of horizontal diaphragm (Fig. 34, d), which as Graber shows contract, and thus aid circulation. The blood is light colored, and entirely destitute of red discs or corpuscles, which are so numerous in the blood of higher animals, and which give our blood its red color. The function of these red discs is to carry oxygen, and as oxygen is carried everywhere through the body by the ubiquitous air- tubes of insects, we see the red discs are not needed. Except for these semi-fluid discs, which are real organs, and nourished as are other organs, the blood of higher animals is entirely. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the origin
Size: 1997px × 1251px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1900, bookdecade1900, booksubjectbees, bookyear1904
